Some influences on a child's future weight begin very early:
Heavier mothers have heavier babies who are more likely to be overweight when they become adults, according to a large, long-term Finnish study. In the U.S., the average weight of moms—and infants—has been rising for decades.
What to do:
If you're overweight and planning another child, consider an eat-right-and-exercise program for six months to drop 5 to 10 percent of your weight before you try to conceive again. And if you smoke, quit. Babies born to smokers are also more likely to grow up overweight.